As the cathode active material of the organic electrolyte cell are known various materials such as carbon fluoride and manganese dioxide. Copper oxide (CuO) is also one of the various cathode active materials and has so high a theoretical electric capacity per unit as 4.25 Ah/cc. Particularly a cell comprising a combination of a lithium anode with copper oxide has a discharge voltage of 1.35 to 1.5 Volts and, therefore, such a cell is interchangeable with a silver oxide cell or mercury cell which is a general-purpose cell, and has excellent shelf stability and resistance to liquid leakage as compared with the general-purpose cell. Therefore, such a cell has been noticed as being attractive as an electric source for precision electronic devices, such as an electronic watch.
However, this cell has such a defect in discharge characteristics that there is a transient voltage drop at an initial discharge stage until the voltage is settled in a constant level. This defect is an important problem when the cell is used in the precision electronic devices such as an electronic watch. Such voltage drop phenomenon as mentioned above inherently occurs in a copper oxide-lithium cell and cannot be eliminated with any electrolyte changed.
One of ways for eliminating such voltage drop is considered that an active material having a higher discharge voltage than that of copper oxide is mixed with the copper oxide and the active material mixed undergoes the reaction preferentially at the initial discharge stage.
In this case, of course, the active material mixed should not be reactive with the copper oxide. On the other hand, however, the discharge voltage should not get two different levels. Therefore, the voltage of a cell comprising a combination of the above-mentioned active material with an lithium anode is desirably approximately equal to or slightly higher than that of a copper oxide-lithium cell and, in addition, the active material should have a high theoretical electric capacity.